Device for hardening



Dec. 4, 1951 J, v s 2,577,611

DEVICE FOR HARDENING -Filed Jan. 2, 1947 4 Sheets-Sheet 1 r I r I I Q 39 35 25 myaw'roz n 5 37 3| .32 J. 20/55/21- EVES ATTOR EY Dec. 4, 1951 J. R. EVES 2,577,611

DEVICE FOR HARDENING Filed Jan. 2, 1947 4 Sheets-Sheet 3 \NVENTOR J. ROBERT El/ES ATTORN Y Dc.4, 1951 J. R. EVES 2,577,611'

7 DEVICE FOR HARDENING lNvENToR J. KO3ERT Eves ATTORNE.

which: will. require little skill and Patented Dec. 4, 1951 UNITE-D STATES PATENT OFFICE to American Optical Company, Southbridge, Mass, a voluntary-association of Massachusetts Application January 2 1947, Serial No. 719,750

sheets, such. as ophthalmic lenses or thelike and One of the principal. objects of the-invention 'is to provide simple; eificientl and economical .means of. rendering glass" articles more resistant to impact. which willfunction automaticallyand ling the position of the article being-hardened inv said furnace; means for automatically controlling the time interval. of heating and means for automatically removing the articlefrom the knowledge of ii-Claims; loL 49-45) has particular reference-teen improved apparartus for accomplishing the above-"results:

generated. within the furnacemeansfor. controla furnace when heated to the controlledtempera+ ture desired and period. of time a:nd.-fo1 subjecting' said heated article to. chillingginfluence. Another object is to'provide: asimple, eflicient and: economical means for'causing anarticleof the above character tohave a portion thereof in compression: and a. portion-in tension. for rendering, said. article more resistant to impact;

Another object is to provide a holding device for the article to be heat treated. which willauto matically center and retain said article in desiredholdi-ng position regardless of the contour shape of. said article both for the position of heating and subsequent cooling, 4

Other objects and. avantages of therinvention will become apparent fromv the; following d'e scription taken in connection with the accompanying drawings and it will. be apparentthat many changes may be madein. thede-tails of con.-

s'truction. and arrangement of parts shown. and described without departing from the spirit of the invention as expressed in the. accompanying claims; It, therefore, is desired not. to limitthe scope of the invention to the particular details of construction an-darrangement of, parts shown and described. as the preferred form only has been given byway of'inustration.

Referring to the drawings: Fig. 1 is a perspectiveview of'the deviceembodying the invention a v Fig. 2'. is a vertical sectional view taken on line 2 -2 of Fig. 1v and looking inthe direction of the arrows;

Fig. 3 is an enlarged fragmentary perspective view having portions thereot shown. in section illustrating a portion. of the. operating. mecha- 2 nism for the lens holding means and door of the furnace; v

Fig. 4 is a fragmentary View showing the lower portion of the furnace in section and illustrating a portion of the door operating mechanism of the furnace; p

Fig. 5 is an enlarged fragmentary sectional view of the holding device and associated mechanism;

Fig. 6 is an enlarged fragmentary view of the latching mechanism for retaining the holder in raised position and automatically functioning means for moving the latch means to releasing position; i V

Fig. '7 is a fragmentary sectional view taken-on line. 'l|' of Fig.3. and looking in: the direction indicated by the. arrows; and 1 Fig. 8. isa schematic view givingthe electrical wiring diagramof the device.

-Referring more particularly to, the drawings wherein like characters of reference designate like parts throughout the several views, the device embodying the invention as shownparticularly in Figs. 1 and 2 comprises a base 9 supporting a housing [0, which housing has a lower hollow compartment l I, an intermediate hollow upright l2 and a hollow upper compartment H3. The lower compartment houses. a rotary air compressor unit M which is of a standard. commercial type embodying a motor 15, a centrifugal blower unit I6 and an air filter IT. The centrifugal blower unit is connected, through suitable pipe lines l8, to a pair of air jets or the like. l9. The

article 26 is supported between a pair of clampv members. 2! carried by spaced uprights 22 which are in turn pivotally connected at 23 to a support 24 mounted .on the'top of the compartment II. The clamp members 2! are in the form of a pair of jaws 25 and 26 having spaced grooved ceramic contacts 2 and 28 for engaging the contour edge of the article to be supported thereby. The jaws 25 and 26 are respectively pivoted at 29 and 30 to the uprights 22 so as to have a free movement relative to said uprights about the pivots 29 and 30 as, a center.

The lower ends of the uprights 22, intermediate the pivots 23, are provided with interlocking connecting means, which in this instance is in the form of a slot 31 formed in one of said members and an interfitting projectionv 32 formed on the other. The member having the projection 32 thereon has a lever 34 associated therewith by means of which the said member may be rocked on its pivot 23. Compression of the lever 34 tends to move the jaw 25 in an outward direction with respect to the jaw. 26 and the interfitting of the connection means 3! and 32 simultaneously imparts a similar movement to the jaw 26 relative to the jaw 25. A spring 35 connected adjacent one of its ends 35 to the support 24 and adjacent its opposed end 31 to the base of the upright 22 tends to retain the jaws normally in adjacent closed relation with each other.

It is particularly pointed out that this type of holding device is self-centering and tends to automatically support the article to be treated.

spaced rollers 4| pivotally connected thereto as illustrated in Fig. 3. The plates 40 have a portion 42 protruding outwardly of one side thereof between which a third roller 43 is pivotally connected. The rollers 4| have a V-shaped peripheral groove 44 therein adapted to engage the bevelled ed e 45' of a vertically disposed guide plate 46. The op osed edge of the guide plate 45 is provided with a similarly formed bevel 41 which is en aged by the bevelled groove of the roller 43. The slide plates 4!! are thereby free to move upwardly and downwardly of the guide plate 45. The said guide plate 46 is secured to the top plate 48 of the lower compartment l I particularlv that portion of the plate which extends inwardly of the hollow intermediateupright l2, see Fig. 2.

In the com artment Hi there is su ported a furnace 49 which may be of the conventional type comprising a metallic housing having insulation material 5| therein and inner resistance heating coils or the like 52. In the bottom of the furnace there is provided a passageway 53 into which the article 29 carried by the holder 2| may be moved. This is brought about by moving the slide 38 upwardly of the guide plate .45 as shown by the full lines in Fig. 2. Adjacent the base of the holder 2! there is provided a plate 54, see Fig. 5-, of refractory material having spaced openings 55 therein through which the uprights 22 extend and which is adapted to form closure means for the passageway 53 when the holder is in raised position.

The slide 38 is provided with a pin 56 adapted to be engaged by a latch member 5! which is in turn pivotally connected to the guide plate 46 as illustrated at 58. The latch 51, adjacent the lower end thereof. is provided with a tapered surface 59 which when the slide 38 is being moved to a raised position is adapted to be engaged by the pin 55 to deflect the latch member in an inward sidewise direction about the pivot 58 thereby permitting the pin 56 to move upwardly beneath the holding portion of said latch. The said latch member 57, has an inwardly extending portion 60 to which one end of a coil spring or the like 5| is attached. The opposed end of the coil spring is attached to the guide plate 46 as illustrated at 62. This normally retains the latch member in holding relation with the pin 56. Adjacent the coil spring or the like 6! there is provided a solenoid 63 having a core portion 34 movportion" 6|] of the latch member.

able in a vertical direction centrally of the solehold 63. The core 34 is provided with a latch connection portion adapted to be en aged by a latch projection 68 formed integrally with the The said portion is provided with an arm $1 disposed in a sidewise direction to the member 6% which is adapted to engage the upper edge 68 of the vertical guide 46 to function as stop means for limiting the inward movement of the end 53.

The solenoid 63, see Fig. 8, is connectedto a timing device 69 which is supported by the front wall of the lower compartment II as shown in Figs. 1 and 2. The said timing device is of the conventional type embodying means which may be adjusted so as to permit the solenoid 63 to be energized after a predetermined lapse of time.

The said timing device is provided with a suitable dial 10 and control knob H for facilitating thissetting. The function of the timing device 69 and solenoid 63 is as follows: When the slide 38 is'moved to its raised position as shown ,by the full lines in Fig. 2, the said slide 38 38 has an adjustable engagement portion 12 thereon adapted to engage the contact 13 of a microswitch or the like 14, carried by the vertical guide member 46, causing the switch to be tripped and to energize the timer 69 starting the cycle of function of the said timer. After a predetermined interval controlled by the setting of the timer, the said timer will cause the solenoid 63 to be energized. The energizing of the solenoid 63 causes the core 64 to be moved in an upward direction moving the arm 60 of the latch member against the tension of the coil spring 6! and simultaneously causing the latch portion 51 to be disengaged from the pin 56 thereby releasing the slide and causing the holder 2| carried thereby together with the article supported in said holder to move in a downward direction. To cushion the downward movement of the slide 38 and the holder and article carried thereby there is provided an air check device 15. This device comprises a cylinder 16 having a piston Tl mounted to be raised or lowered therein. The piston 11 is carried by an arm i8 which is in turn connected with the silde 38 as shown at 19. It is to be understood that when the slide 38 is in its raised position the piston 11 will also be raised with respect to the cylinder 16 so that downward movement of the slide 38 will cause the piston 11 to simultaneously move downwardly of the cylinder 16. This downward movement of the piston 11 causes an air pressure to be built up inwardly of the cylinder 16 and functions as cushion means for cushioning the downward movement of the slide. To provide for a smooth functioning arrangement the said cylinder 15 beneath the piston H is provided with an adjustable bleeder valve for controlling the exhaust of the compressed air according to the amount of cushioning desired.

The slide 38, as shown in Figs. 2 and 7, is provided with additional adjustable engagement means 8| which, when the slide 38 is in its lowermost position, is adapted to engage the contact 82 of a microswitch or the like 83 which, as shown in Fig. 8, is electrically connected with the rotary air compressor l4. This energizes the motor l5 causing the said motor to rotate the centrifugal blower unit which in turn forces air through the nozzles l9.

It is to be noted that this downward movement of the slide 38 causes the holder 2| to move downwardly between the nozzles l9: and; toiautomaticallv move the: article: into aligned relationship. withthes-nozzles... 1

: This downward: movement. of. the. slide 38 moves the engagement member. 12 outof; contact with the micro'switch. I4 thereby de-energizing the. timing device. 69; and also de-energizing the solenoid 63., The. said: timing: device is: then again ready to function ina repetitive manner. The slide: memberz38, as shown in: Fig. 3; has secured thereto anangularly disposed'iraming. 84 havinga base plate. 85 thereon. Thepbase. plate 8% is: adapted to be engaged by a:cam member-86 carried'by 'a. shaft 81'. The. shaft. 81 is; iournaled in. bearings 88 carried by'the plate- 48,and1is;operated; by means. of: a hand. lever orythelike 89.

This cam member: 86. provides means whereby the slide 38 may be raised to move the engagement means: 81. out of contact with the plunger 82 of the switch. 83 to deenergize the motor [5' and thereby check the flow of air through the jetsl9. This is a manually controlled arrangement by 'means' of which the flow of. air may be shut ofi after the article has been properly chilled. The framing 84, adjacent the upper end there:

' of, isrprovided with: a'cam portion 90 adapted to engage a. roller 9 I carried: by a crank member 92'.

The crank member'92t is connected with a shaft 93 journaled in the spaced bearings 94: and: to which a. door or shutter member 95 is attached.

ried by the base of the furnaceadjacent the passageway 53. a The door or shutter '95 is normally held in closed'position relative tothe passageway 53 by means of a coil spring or the like 96 having one of its" ends anchored; in the bearing: 94 and the other of its ends 97: latched" with. the side portion of the dooror shutter 95-, see Fig. 3. The function of the door is substantially as follows: When the slide 38 and associated? holder 21 is in its lowermost position, as. shown by the dash lines in Fig. 2', the coil spring 96 is free to hold the door or'shutter 95 in closed relation with the passageway 53. When. the slide'38 is. moved toits raised position, asshowir by the full lines in Fig. 2 and by reference to Fig. 3,.the'cam'portion 90' will first engage the roller 91? causing the crank 92 to rotate the shaft 93" and move the. door or shut-- plate 5.4 then functions to closethe: passageway.

Upon the movement of" the slidev 3% to its lower.- most' position the cam roller will move upwardly of. the edge 93 inwardly of the cam-portion 93 and will then permit the coilspring toretain: thev door in closed. position.

.It. has: been described above that the furnace 49 is heated by "means of suitable resistance coils 52'. In electrical connection therewithis provided a suitable controller 99: for regulating and maintaining the temperature of heat in. the furnace at a controllable uniform temperature. In hard.-

ening glass. articles, best results are achievedwhenthe variation of. temperature inthe-iurnace can be; keptv withina minimum range; during; the actualheating; of. the article. Inthisv respect, the potentiometer type; controller; 99 has. proven most satisfactory; although, of course, any of the other conventional controllers could be used. Through the use of apotentiometer type controller, applioperate inthe conventional manner.

faces of the lens.

In utilizing the device, to harden a lens or other glass article, the operator must first determine the .average thickness of the lens. From this dimension, he computes the time interval for which thelens is to be heated, based, of course, on the temperature at..which the furnace is being run.v Obviously, the higher the temperature in the furnace, the shorter will be-the period of treatment. In keeping with the objects of the invention, a chart is preferably prepared for use with the device wherein time intervals of heating as based on different temperature have been worked out for the usual thicknessesof lenses encountered. This will both speed up the operationand reduce the chances. of error in. calculation. I

Thus, the operatoradjusts the control setting switch-1 tilt and, timer 68 according to the values foundon. the chart for the particular thickness of. lens tobe hardened. When the furnace is completely saturated with heat to the desired temperature, as indicated by pilot light N3, the lens is placed between the clamp members 2! of the holding device and manually raised by the handle 34 into the furnace. The door to entrance- 5.3 automatically opens to permit the insertion of the holder and automatically closes upon its removal. When the holder has been raised into the furnace, it is automatically held therein by the latch 51' and the timing device 69 'is'simultaneously started, At the end of the time cycle, the timing device energizes the solenoid 63 causin the core 6'4 to rise and delatch the holder. The holder immediately drops under the action of gravity with the air check device 15 cushioning its fall and causing the holder to be moved to its initial position between the air jets it. As the holder reaches its position between the air jets, the engagement portion 8! carried by slide member 38 contacts plunger 82 of microswitch 83, starting the air compressor unit l4. Cooling blasts of air'are thereupon direeted through jets l9 onto the opposed side sur- When'the lens has been sufficiently chilled, the contact between engagement portion 81' and plunger 82 may be broken by depressing lever 89. This de-energizes and therefore shuts ofi the rotary air compressor. The lens is then removedv from the holder by depressing handle 34 and the hardening unit. is ready for repeating the process.

. From the foregoing, it is believed that exceedingly simple and efiicient means and method have been provide. for, accomplishing all of the objects and advantages or the invention.

Having described my invention, I claimf 1. A device of the character described comprising a heating chamber having an entrance opening thereto, cooling means spaced from said entrance opening to the heating chamber, and a work holder movable to and from a pair of positions, one of said positions being so located as to cause work carried by the work holder to be supported so as to be chillable by the cooling means, and the second of said positions being so located as to cause the work to be held in the heating chamber, said work holder having an engageable portion, and supporting means adjacent said second position for releasably engaging said portion of the work holder when in said second position to overcome a force tending to urge the work holder to return to the first position, control "means for disengaging said supporting means from the engageable portion of the work holder upon elapse of a predeterminable interval of time to allow said force to return the work holder to said first position, said control means bein operable by movement of the work holder into said second position where the work is held in the heating chamber.

2. A device of the character described comprising a heating chamber having an entrance opening thereto, jet means spaced from said entrance opening to the heating chamber, and a work holder movable to and from a pair of positions, one of said positions being so located as to cause work carried by the work holder to be supported in alignment with the jet means, and the second of said positions being so located as to cause the work to be held in the heating chamber, said work holder having an engageable portion, and a movable latch member adjacent said second position adapted to be moved into place to engage said engageable portion of the work holder so as to cause the work holder when in said second position to resist a force tending to urge the work holder to return to the first position, control means energizable by a source of electrical energy for moving said latch member to a position where it will cease to engage said portion of the work holder upon elapse of a predeterminable interval of time whereby said force will cause the work holder to return to its first position, and switch means for energizing said control means, said switch means being operable by movement of the work holder to said second position where the work is held in the heating chamber.

3. A device of the charactcr described comprising a heating chamber having an entrance opening in a wall portion thereof, closure means pivotally connected adjacent said wall for closing said entrance opening and spring actuated means for normally urging said closure means in closed relation over said entrance opening, a cooling unit in spaced relation to said entrance opening, and a work holder mounted for movement from a position in the cooling unit to a position in the heating chamber, cam means carried by said work holder and a cam follower carried by the closure means, said cam follower engagin the periphery of the cam means, and with said cam means being of such a peripheral shape as to cause the cam follower to pivot the closure means into an open position about its pivotal axis as the work holder is moved toward the entrance opening to the heating chamber and sufficiently to permit the work holder to pass through said entrance opening.

4. A device of the character described comin the cooling unit to a position in the heating chamber, cam means carried by one of said members and a cam follower carried by the other member, said cam follower engaging the periphery of the cam means, and with the periphcry of said cam means being of such shape as to cause the closure member to be moved by cooperation with the cam follower into an open position as the work supporting member is moved toward the entrance opening to the heating chamber and sufiiciently to permit the work supporting member to pass through said entrance opening.

5. A hardenin device of the character described comprising a heating unit and a chilling unit in spaced relation, a work holder, and means for restricting said Work holder to a course of movement between a pair of stations, one of said stations being so located that work held thereby is positioned to be chilled by the chilling unit and the other station being so located that said work held thereby is positioned to be heated by the heating unit, and latch means for maintaining the work holder at said latter station where the work is positioned to be heated, said work holder having a contact portion, and switch means positioned adjacent said latter station to be contacted by said contact portion of the work holder when moved to said station, said witch means being adapted on contact by the contact portion of the work holder to cause the latch means to unlatch the work holder at the end of a predeterminable period of time whereby the work holder will be returned to the first station to position the work to be chilled by the chilling means.

6. A hardening device of the character described comprising a heating chamber and jet means spaced therefrom through which chilling gases are adapted to flow, a work holder, and means for restricting said work holder to a course of movement between a pair of stations, one of said stations being so located that work held thereby is positioned in alignment with the jet means and the other station being so located that said work held thereby is disposed in the heating chamber, latch means for maintaining the work holder at said latter station, and a pair of switch means adjacent each end of said course of movement, each adapted to be operated by movement of said work holder to a respective station adjacentsaid ends, the switch means adjacent said latter station being adapted to cause the latch means to unlatch the work holder at the end of a predeterminable period of time whereby the work held by the holder will be removed from the heating chamber and the holder returned to the first station where the Work will be aligned with the jet means, said jet means being controlled by the switch means adjacent the other end of the course to cause chilling gases to flow through the jet means when the work is aligned therewith.

'7. A hardening device of the character described comprising jet means through which chilling gases are adapted to flow and a heating chamber spaced in overlying relation therewith,

a work holder, and means for restricting said work holder to a course f.m0vement between a lower and an upper station, the lower station being so located that work held thereby is positioned in alignment with the jet means and the upper station being so located that said work held thereby is disposed in the heating chamber, latch means for maintaining the work holder at said upper station, and a pair of switch means adjacent each end of said course of movement, each adapted to be operated by movement of said work holder to a respective station adjacent said ends, the switch means adjacent said upper station bein adapted to cause the latch means to unlatch the work holder at the end of a predeterminable period of time to'cause the holder to return to the first station where the work will be aligned with the jet means, said jet means being controlled by the switch means adjacent the other end of the course to cause chilling gases to flow through the jet means when the work is aligned therewith.

8. A hardening device of the character described comprising a heating. chamber and jet means spaced therefrom through which chilling gases are adapted to flow, a work holder having contact means thereon, means for restricting said work holder to a course of movement between a pair of stations, one of said stations being so located that work held thereby is positioned in alignment with the jet means and the other station being so located that said work held thereby is disposed in the heating chamber, latch means for maintaining the work holder at said latter station, and a pair of switch means adjacent each end of said course of movement, each adapted to be operated by the contact means of said work holder when said holder is positioned at the station adjacent said respective ends, the switch means adjacent said latter station being adapted to cause the latch means to unlatch the work holder at the end of a predeterminable period of time whereby the work held by the holder will be removed from the heating chamber and the holder returned to the first station where the work will be aligned with the jet means, said jet means being controlled by operation of the switch means ad- 10 jacent the other end of the course to cause chilling gases to flow through the jet means when the work is aligned therewith.

9. A hardening device of the character described comprising a chilling unit and a heating unit in spaced aligned relation, a movable work holder for supporting work in cooperative relation with said respective units, guide means restricting the movement of the work holder to a course between a pair of stations, one station being located so that the work may be positioned in cooperative relation with the heating. unit and the second station being located so'that the work may be positioned in cooperative relation with the chilling unit, restraining means for maintaining the work holder at said first station against a force urging the work holder to move to the second station, releasing means actable on said restraining means to freethe work holder for movement by said force to the second station, a timing device rendered operative with the movement of the work holder to said first station where the work held thereby is positioned in cooperative relation with the heating unit, said timing device being cooperatively connected with the releasing means and adapted to cause said releasing means to act upon elapse oi. a determinable period of time as controlled by said timing device whereby automatically the work is released to move into cooperative relation with the chilling unit, and saidtiming device being adjustable whereby the period of time during which the work is held in cooperative relation with the heating unit may be controlled according to the characteristics of the work being treated.

. J. ROBERT EVES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

